Do vehicles that use deisel fuel have to pass the emissions test?

Question

I was behind a truck that had black smoke coming out of it. Someone said "that is diesel fuel" I said "don't they have to pass the emissions test" the person next to me had no idea. This vehicle was a commercial vehicle. Do they have to pass? do cars that use diesel have to pass? If not, can you tell me why not?

Answer 1

In California, we have a diesel pick up truck. They have very strict emission control here, but  we do not have to pass a "smog" test. Even though diesel can be smelly, it is actually cleaner to burn then gas. With that said, here in California, if black smoke is coming out of your exhaust, CHP will pull you over. For big rigs the rules are is the smoke dissipates over the top of the big rigs in like about 4 ft, then that is fine. It is not fine if it is spewing black smoke. Our pick up does not have any black smoke coming from it what so ever.

Answer 2

In states that require emissions testing, diesel vehicles have to pass too. The tests are actually more stringent for diesel vehicles, but all states don't require emissions tests. New Jersey will test trucks on the side of the road, some other states will too and some states could care less.

Answer 3

Yes but commercial vehicles have different requirements than personal vehicles.

Answer 4

in california they do not have to pass an bi-annual emissions test....yet (word is in 2009/10 they will).  However, if a police officer sees a heavy truck emitting excessive "black smoke" from the exhaust they will get written up.

Answer 5

Yes, depending when the car was made. New cars must meet emission requirements whether Diesel or not

Answer 6

It depends what year the vehicle was made. Older engines have less stringent emission requirements than newer ones.